Inventory guides for counts, reorders, and locations.

A reorder point is the inventory level that triggers a replenishment order before you stock out. Formula: ROP = (Average Daily Usage × Lead Time in Days) + Safety Stock. Set it for the items where shortages cost a job, a customer, or a margin. Ignore it for the long tail until you have usage data.

Safety stock is the buffer inventory you hold above expected demand to absorb usage spikes and supplier delays. The simplest formula: Safety Stock = (Maximum Daily Usage × Maximum Lead Time) − (Average Daily Usage × Average Lead Time). A more precise version uses a Z-score and demand variability. Most small teams should start with the simple one and graduate when the data earns it.

Cycle counting is a recurring partial count of inventory that keeps records accurate without halting operations. A physical inventory is a full count of everything, usually done annually. Most small and mid-sized teams should rely on weekly cycle counts for 90% of accuracy work and run a full physical once a year for finance.

Barcode inventory is the practice of identifying items, locations, and movements with machine-readable codes instead of typed entries. The point is not speed. It's removing the manual typing step from the moments where attention is lowest: receiving, counting, transferring, picking. Done well, barcoding is the cheapest accuracy investment a small business can make.

Multi-location inventory has three layers: bin, location, region. Track stock at every physical place it rests, with separate quantities, separate reorder rules, and a clear record of every movement between locations. Get the location hierarchy and transfer accountability right and the rest of the system follows. Get them wrong and every report lies.

In vendor managed inventory (VMI), the supplier watches the stock they sell you and decides when to replenish it, instead of waiting for you to notice you're low and cut a PO. It can stop the stockouts that come from nobody owning the count. It can also go quietly wrong when the supplier is working off numbers you can't see and can't check.